What is Pct in blood test results?

[Rosie10]

Anyone know what Pct is (in Platelets) in a Hematology blood test? and does anyone know what the normal values for Pct are? It doesn’t give any values on the test results sheet.

My horse has had lots of blood tests and having looked at the last five tests over the last 15 months her platelets have been between 95 and 198 (normal 100-400) and Pct usually between 0.5 -0.10%.

In March her Platelets were 171 (100-400) and Pct 0.9%. Six weeks later her Platelets have gone up to top end of normal being 378 (100-400) and PCT is 0.22%. MPV and PDW similar to previous results over last 15 months. Differential is normal and Wbc and Rbc are all well within normal and similar to previous results.

So why the suddenly higher Platelet and Pct result?

Her Creatinine was higher too, 180 (10-176) which is not normal for her although tested again couple weeks ago and is back in normal 172 (10-176). It has normally been between 102 and 120 over last three years. In Feb it was 141, end of April 180 (10-176).

Could the higher Platelet/Pct be to do with the higher creatinine?

If you got this far thanks for reading!

[KariW]

Pct measures Procalcitonin levels in the blood. High Pct levels may indicate a bacterial systemic infection or severe inflammation, of some type. I’m not a vet, so you may want to have your vet go over the test results in detail.

[Risuena]

I think that in this context, PCT is plateletcrit, which essentially measures a combination of platelet count and size, so you could have the same PCT with many smaller platelets, or with fewer larger platelets. With a PCT of 22%, my first thought would be lab error – perhaps it was 0.22%?

Your lab must use different units for creatinine than what I’m used to (mg/dl) – our high normal is about 1.5. I’m not an internal medicine guru, so I could be unaware of some things, but in general the changes in platelet numbers are unlikely to be directly related to the creatinine. Platelet counts do vary under normal conditions (and also related to external factors like some clotting/clumping after blood collection) and while your horse’s platelet numbers have fluctuated, they’ve been within the normal range, so not something I’d worry about. Looks like her creatinine has been at the high end of the range, so that might something to keep an eye on over time.

[Rosie10]

[QUOTE=Risuena;8176549]
I think that in this context, PCT is plateletcrit, which essentially measures a combination of platelet count and size, so you could have the same PCT with many smaller platelets, or with fewer larger platelets. With a PCT of 22%, my first thought would be lab error – perhaps it was 0.22%?

Your lab must use different units for creatinine than what I’m used to (mg/dl) – our high normal is about 1.5. I’m not an internal medicine guru, so I could be unaware of some things, but in general the changes in platelet numbers are unlikely to be directly related to the creatinine. Platelet counts do vary under normal conditions (and also related to external factors like some clotting/clumping after blood collection) and while your horse’s platelet numbers have fluctuated, they’ve been within the normal range, so not something I’d worry about. Looks like her creatinine has been at the high end of the range, so that might something to keep an eye on over time.[/QUOTE]

Thank you both for your replies. Risuena thanks for explaining that and yes sorry Pct is 0.22%.

[Horsegal984]

Everything Risuena said. I would monitor the creatinine but the fluctuation in platelets/pct isn’t anything but normal variation. It is highly influenced by the quality of the blood draw and the sample handling, for example a poor stick where the vet has to hunt for the vein or the blood runs slowly into the tube is likely going to have lower platelets than a good clean stick. If the platelets came back very low, say 50, then the lab would do a blood smear to look for clumping, which the machine will misread and cause a falsely low count.

I have had a new tech pull a CBC on a cat and the platelets came back as 28(!!) so we had a more experienced tech redraw and the count was 200. The first stick had partially clotted in the tube, which uses up the platelets.